webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 139 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/InferredValue.cpp b/Source/JavaScriptCore/runtime/InferredValue.cpp
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+++ b/Source/JavaScriptCore/runtime/InferredValue.cpp
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+/*
+ * Copyright (C) 2015-2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "InferredValue.h"
+
+#include "JSCInlines.h"
+
+namespace JSC {
+
+const ClassInfo InferredValue::s_info = { "InferredValue", 0, 0, CREATE_METHOD_TABLE(InferredValue) };
+
+InferredValue* InferredValue::create(VM& vm)
+{
+    InferredValue* result = new (NotNull, allocateCell<InferredValue>(vm.heap)) InferredValue(vm);
+    result->finishCreation(vm);
+    return result;
+}
+
+void InferredValue::destroy(JSCell* cell)
+{
+    InferredValue* inferredValue = static_cast<InferredValue*>(cell);
+    inferredValue->InferredValue::~InferredValue();
+}
+
+Structure* InferredValue::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
+{
+    return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
+}
+
+void InferredValue::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    InferredValue* inferredValue = jsCast<InferredValue*>(cell);
+    
+    auto locker = holdLock(*inferredValue);
+    
+    if (inferredValue->m_set.hasBeenInvalidated()) {
+        if (inferredValue->m_cleanup && !inferredValue->m_cleanup->isOnList())
+            inferredValue->m_cleanup = nullptr;
+        return;
+    }
+    
+    JSValue value = inferredValue->m_value.get();
+    if (!value)
+        return;
+    if (!value.isCell())
+        return;
+    
+    if (!inferredValue->m_cleanup)
+        inferredValue->m_cleanup = std::make_unique<ValueCleanup>(inferredValue);
+    visitor.addUnconditionalFinalizer(inferredValue->m_cleanup.get());
+}
+
+InferredValue::InferredValue(VM& vm)
+    : Base(vm, vm.inferredValueStructure.get())
+    , m_set(ClearWatchpoint)
+{
+}
+
+InferredValue::~InferredValue()
+{
+}
+
+void InferredValue::notifyWriteSlow(VM& vm, JSValue value, const FireDetail& detail)
+{
+    ASSERT(!!value);
+    switch (m_set.state()) {
+    case ClearWatchpoint:
+        m_value.set(vm, this, value);
+        m_set.startWatching();
+        return;
+        
+    case IsWatched:
+        ASSERT(!!m_value);
+        if (m_value.get() == value)
+            return;
+        invalidate(vm, detail);
+        return;
+        
+    case IsInvalidated:
+        ASSERT_NOT_REACHED();
+        return;
+    }
+    
+    ASSERT_NOT_REACHED();
+}
+
+void InferredValue::notifyWriteSlow(VM& vm, JSValue value, const char* reason)
+{
+    notifyWriteSlow(vm, value, StringFireDetail(reason));
+}
+
+InferredValue::ValueCleanup::ValueCleanup(InferredValue* owner)
+    : m_owner(owner)
+{
+}
+
+InferredValue::ValueCleanup::~ValueCleanup()
+{
+}
+
+void InferredValue::ValueCleanup::finalizeUnconditionally()
+{
+    JSValue value = m_owner->m_value.get();
+    
+    // Concurrent GC means that this could have changed since we installed the finalizer.
+    if (!value || !value.isCell())
+        return;
+    
+    if (Heap::isMarked(value.asCell()))
+        return;
+    
+    m_owner->invalidate(*m_owner->vm(), StringFireDetail("InferredValue clean-up during GC"));
+}
+
+} // namespace JSC
+